Plus One

Given a number represented as an array of digits, plus one to the number.

class Solution {public:    vector<int> plusOne(vector<int> &digits)    {        int len = digits.size();        int i;        int a[len+1];        memset(a,0,sizeof(a));        int carry = 1;        for(i=0;i<len;i++)        {            a[len-i] += (carry + digits[len-i-1])%10;            carry     = (carry + digits[len-i-1])/10;        }        if(carry == 0)        {            for(i=0;i<len;i++)            digits[i] = a[i+1];            return digits;        }        else        {            a[0] = 1;            for(i=0;i<len;i++)            digits[i] = a[i];            digits.push_back(a[len]);            return digits;        }    }};